Piping systems are well-known for conveying fluids or slurries between locations. Common practice in such applications is to provide a tee-piece in the pipeline. The branch of the tee-piece accommodates a plug which is anchored in position to close the branch during normal flow. If it is necessary to relieve an overpressure condition in the pipeline, an anchoring device, such as a clamp, may be released, freeing the plug to retreat in the branch.
One problem which can be encountered in this operation is rapid release of the plug and pipe contents, creating a danger for personnel in the vicinity. Another potential problem is that slurry conveyed in the pipeline can jam the plug in the branch. Considerable force, for example produced by blasting, may then have to be applied to release the plug.
The present application seeks to provide an apparatus which addresses one or more of these potential problems.